Concept:Inbreeding raises homozygosity, exposing harmful recessive traits in offspring.
Explanation:Inbreeding involves mating between closely related individuals, such as siblings or cousins.
Closely related individuals share a large proportion of their genes because they descend from a common ancestor.
Therefore, both parents are more likely to carry the same recessive alleles for hereditary defects.
This greatly increases the chance that a child will inherit two copies of a harmful recessive allele, giving the genotype
aa.
Such a child will express the disease instead of remaining a healthy carrier of the genotype
Aa.
Common examples include sickle-cell anaemia, haemophilia, and cystic fibrosis.
This is why inbreeding is strongly discouraged in humans.
Answer:D. lead to outbreak of hereditary diseases.